Touch-type keyboard with character selection through finger location on multifunction keys

ABSTRACT

A touch-type keyboard with multiple functions associated with each key which functions are uniquely selected based on finger position. Each of a plurality of mechanical keys are associated with at least three functions. Each key has a surface area for actuation by a user&#39;s finger. The surface area is mapped to zones associated with each function. Function actuation is determined by detection of the finger position when the key is actuated. In the event of a finger overlapping multiple zones during actuation, unique function selection is determined at least in part from the pattern of finger overlap with the plural zones.

BACKGROUND

1. Field of the Invention

Embodiments of the invention relate to a keyboard. More specifically,embodiments of the invention relate to a compact, portable, wirelesskeyboard for use with mobile devices.

2. Background

Portable devices such as smartphones like the iPhone™ and Android™-basedphones, as well as tablet computers such as the iPad™, have becomeubiquitous and their market share in the overall computing field hascontinued to grow. A dominant complaint of users of such devices is theabsence of a real keyboard for efficient typing. Efforts to address thisproblem have followed two general tracks: (i) repurposing existingcompact keyboards to interface with these devices or (ii) creatingcompact “candy bar” keyboards, which are unsuitable for touch-typing. Aproblem with the first track is that the resultant keyboard is oftenbigger than the device for which it is designed to operate. As a mobileoffice option, this results in the tablet-keyboard combination beinginferior to available laptops as the marginal gain in smaller size andweight is insufficient when compared to the functionality and computingpower of available laptops. In the second case, shrunken form-factorkeyboards are not satisfactory for touch-typing. While they willgenerally have keys arranged in a touch-typing format such as QWERTY,their physical size renders touch-typing impossible. It would thereforebe desirable to develop a compact keyboard suitable for touch-typing.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example and notby way of limitation in the figures of the accompanying drawings inwhich like references indicate similar elements. It should be noted thatdifferent references to “an” or “one” embodiment in this disclosure arenot necessarily to the same embodiment, and such references mean atleast one.

FIG. 1 is a diagram of one embodiment of the invention with elementsdissociated.

FIG. 2 is a diagram of the keyboard of FIG. 1 rotated to expose themagnetic masses.

FIG. 3 is a diagram of a system of one embodiment of the invention.

FIG. 4 is a front profile view of a keyboard of one embodiment of theinvention with one key depressed.

FIG. 5 is a diagram of a key base of one embodiment of the invention.

FIG. 6 depicts a flexible circuit board for a key array of oneembodiment of the invention.

FIG. 7 is a diagram of a key mechanism assembly according to oneembodiment of the invention with the keycap removed.

FIG. 8A is a cross-sectional diagram of a key of one embodiment of theinvention in a depressed configuration.

FIG. 8B is a sectional diagram of the key of FIG. 8A in a rest stateorientation.

FIG. 9 is a cutaway view showing a single link of one embodiment in theinvention.

FIG. 10 is a bottom view of a key of one embodiment of the inventionwith the key base removed.

FIG. 11 is a sectional view of a bottom view of selected parts of a keyfor one embodiment of the invention with the key base removed.

FIG. 12 is a diagram of the spacebar with the cover removed.

FIG. 13 shows a flex circuit for a spacebar of one embodiment of theinvention.

FIG. 14 is a further view of the spacebar with the cover and flexcircuit removed.

FIGS. 15A and 15B are diagrams of the link mechanism in an up and downorientation, respectively.

FIG. 15C is a sectional view of the interconnection between the spacebarand the key arrays.

FIG. 16 is a perspective view of the spacebar with the beam partiallyinserted.

FIG. 17 is a view of the beam coupled to a host and spacebar.

FIG. 18 is a perspective view of one embodiment of the invention in astowed orientation.

FIG. 19 is a perspective view of the bottom side of the clip.

FIG. 20 is a flow diagram of the operation of one feature of oneembodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 is a diagram of one embodiment of the invention with elementsdissociated. Keyboard 100 includes three physically dissociableelements; two key arrays 102, 104, and a spacebar 106. A first array ofkeys 102 and a second array of keys 104 are dissociable from each otheras well as a third element, spacebar 106, that provides spacebarfunctionality to the keyboard 100. In the shown embodiment, the firstarray of keys 102 has four keys described by the letters on their faces:“RTFGVB” key 112, “EDC” key 122, “WSX” key 132 and “QAZ” key 142. Keyarray 104 also has four keys: “YUHJNM” key 114, “IK” key 124, “OL” key134 and “P” key 144. Touch typists will recognize that the letters orfunctions associated with each key are those actuated by an individualfinger during touch-typing. While the mapping in this FIG. 1 follows thescheme of a QWERTY touch-typing keyboard, any other touch-typing mappingmay be employed.

Thus, the left index finger actuates key 112, the left middle fingeractuates the functions of key 122, the left ring finger actuates thefunctions of key 132 and the left little finger actuates the functionsof key 142 when a user is touch-typing with keyboard 100. Similarly, theright index finger actuates the functions of key 114, the right middlefinger actuates the functions of key 124, the right ring finger actuateskey 134 and the right little finger actuates key 144. The functionsassociated with each respective key are the same as would be actuated bythe corresponding finger in the touch-typing system employed (in thisexample QWERTY). In one embodiment, a tactile feature such as a raisedarea or concave area denotes the “home row” location for each finger.While in this embodiment 8 total keys are employed, embodiments of theinvention may have more or fewer physical keys. For example, in oneembodiment keys 122 and 132 could be combined into a single largerphysical key. In another embodiment for example the larger keys such askey 112 may be rendered as two keys for example an “RFV” key and a “TGB”key.

In one embodiment, magnetic masses are disposed within each ofdissociable elements 102, 104, 106 such that the magnetic forces therebetween draw dissociable elements together to form a unitary keyboard.As used herein, “magnetic mass” includes permanent magnets and massescomprising magnetic material upon which a magnet may exert an attractiveforce. In one embodiment, rare-earth magnets are disposed in each ofdissociable elements 102 and 104, and a steel mass to which those rareearth permanent magnets may magnetically attract is disposed indissociable element 106. Applying sufficient force to overcome therespective magnetic attractions can disassociate the different elements.In one embodiment a force of about one pound will result indisassociation of the elements. Use of stronger or weaker magnets iscontemplated as within the scope of different embodiments of theinvention. In one embodiment, when the magnets draw the dissociableelements together the device is automatically activated.

In an alternative embodiment, elements 102, 104 and 106 interconnectusing any form of conventional electrical interconnection, includingmale/female connectors. In one embodiment, wire leads may be used tointerconnect the three elements. In still a further embodiment, thedissociable elements need not be interconnected for operation. Rather,each dissociable element 102, 104, 106 includes a wireless signalingmodule, such as a Bluetooth™ module, which permits them tointercommunicate and/or communicate individually directly with a host.In one such embodiment, the key arrays can be powered by a near fieldtransponder resident in the spacebar. Such a transponder could comprisea near field communication (NFC) chip that is operated by radio wavesemitted by another of the dissociable elements or the host.Electromagnetic waves emitted by one element may be received inductivelyand converted into usable power to supply another element.

FIG. 2 is a diagram of the keyboard of FIG. 1 rotated to expose themagnetic masses. Array 102 and array 104 are coupled together bypermanent magnets (not shown). Additionally, array 102 includes magnet202 and magnet 212 which are attracted to magnetic mass 206 in spacebar106. Similarly, key array 104 includes magnets 214 and 204, which arealso attracted to magnetic mass 206. Magnets 212 and 214 in key arrays102 and 104 respectively, are arranged to expose opposite magneticfields, e.g. 214 may expose a north polarity and 212 a south polarity orvice versa. In one embodiment all of the permanent magnets arerare-earth magnets. As discussed in more detail below, magnetic mass 206has a topology to ensure a strong magnetic attraction between key array102, key array 104 and spacebar 106.

In this embodiment, magnet pairs 202, 212 and 214, 204 each form a powerand ground path such that a battery (not shown in this figure) in thespacebar 106 can power the operation of both key arrays 102, 104.Moreover, the magnetic coupling between the two key arrays serves toprovide a redundant power connection so that if one power path fails,the array can source its power through the adjacent array. In additionto forming the power path, the magnetic interconnection also forms thesignaling path by which data is passed from each key array to thespacebar 106 for transmission to a recipient device. By electronicallydisconnecting power, the same path may momentarily be used to transmitdata back and forth, without additional connections. This data mayinclude keyboard array data, such as key press events and the valuesassociated therewith for interpretation by a processor (not shown inthis figure) within the spacebar.

For example in one embodiment, magnets 212, 214 provide ground andremain connected both while providing power and when signaling. Magnets202, and 204 are connected through a switch to a power source in thespacebar 106. The power charges a capacitor in each of the arrays 102and 104. These capacitors are used to power the respective arrays 102,104 while the switch disconnects the power to magnets 202 and 204 sothat they can alternately be used as a signal path. Unlike aconventional power line modem, the power is actually disconnected duringsignaling rather than simply modulating its voltage with the datasignal. In this example, if e.g. the J function is activated, the array104 generates a “make code” for key 114 and a location code indicativeof the user's finger position when the key was depressed. When the keyis released a “break” code is generated. In some embodiments, the array104 may also predict the “J” and include a J prediction code. Thesecodes are buffered in the array 104 until a sending opportunity arises.In one embodiment, for a given key function, these codes may amount toapproximately ten bytes of data.

In one embodiment, the spacebar 106 periodically disconnects the power(via the switch) and listens for data from the arrays 102, 104. Thecodes are sent to the spacebar using, in one embodimentnon-return-to-zero encoding (NRZ) at a 100 kHz bit rate. The processor(not shown in this figure) in the spacebar 106 interprets the incomingcodes and sends out (in this example) a “J make” and then a “J break”code to the recipient device via a wireless link. The prediction code(if supplied) may be compared with information known to the spacebar 106(but not necessarily to the array 104) such as different command modesetc. In the case that a different mode is operative, the spacebar 106generates the appropriate codes to forward along to the recipient togenerate the expected function.

Additionally, the spacebar 106 ensures that the battery power will bereconnected before the droop in the capacitor voltage would result inloss of power in the array 102,104. In one embodiment, the array 102,104 requires about three mA for normal operation. In one suchembodiment, the spacebar 106 prevents signaling longer than 3 ins, toassure that the capacitor voltage does not droop too far. At 100 kHz, 1bit is sent every 10 μs. Each 8 bit byte of data, requires ten bits tobe sent (due to overhead). This permits thirty bytes of data to betransmitted in each three ms slot. These 3 ms slots are fit in betweencharging periods, which should not exceed five ms to avoid excessivedroop. In this example, each time the spacebar 106 provides batterypower to charge the arrays, it should do so for at least 0.5 ms toinsure sufficient charge in the capacitors to avoid excessive droopduring a transmission slot.

Each time the spacebar 106 signals an array 102,104, the array 102, 104responds back with an acknowledgement that it has received an accuratecopy of the data, and the array 102, 104 also delivers any key code datait may have. The spacebar 106 checks to confirm that the response wasvalid, and the process repeats. When the spacebar 106 finishes signalingthe array 102, 104, the spacebar 106 connects the power line to batterypower for 0.5 ms to recharge the capacitors in the arrays 102, 104.After this, the spacebar 106 disconnects battery power. When the array102, 104 detects the end of the spacebar 106 signaling, it drives thepower line to a logical high level for 0.8 ms. This logic high overlapswith the 0.5 ms charge time, and remains active for about 0.3 ms afterthe charge period (varies based on the relative precision of the clocksin the spacebar 106 and arrays 102, 104). The 0.3 ms window establishesa quiet period prior to the start of the array 102, 104 signaling itsdata to the spacebar. The array 102, 104 then signals the spacebar 106for up to 3 ms. At the end of the array 102, 104 signaling, the array102, 104 sets the power line to a logic high level for 0.3 ms to insurea clean handoff of control back to the spacebar 106. Also at the end ofthe array 102, 104 signaling, the spacebar 106 reconnects the battery tothe power line for the next 0.5 ms charge period, and the processrepeats for the next set of data back and forth. In one embodiment, thespacebar 106 is master of the communication, and sequentially addresseseach array 102 and 104 so as to prevent contention of responses.

FIG. 3 is a diagram of a system of one embodiment of the invention. Arecipient device 320 having a display 322 is retained at a desirablework angle by a dual function stand/clip 324. Recipient device 322 maybe a smartphone or tablet computer. It is also envisioned that thekeyboard of the embodiments in the instant invention may be used withdesktop computers or with any other electronic device for which akeyboard is desirable. “Recipient” as used here in is deemed to includeany device that receives inputs from the keyboard. As explained in moredetail below, in addition to functioning as a stand for a recipientdevice 320, clip 324 provides a stowage holder for the disassembledkeyboard.

The key array 102, key array 104 and spacebar 106 are all individuallyand collectively frameless. This reduces the space required to supplythe keyboard functionality. Once assembled, as shown, the keyboard hasan “underlined V” shape. This underlined V-shape provides greaterergonomic comfort in reduced space relative to conventional keyboardscomprised of staggered linear rows of buttons. Nevertheless otherembodiments of the invention may occupy greater space and have astandard linear arrangement. In one embodiment, assembling the deviceturns it on and disassembling the device turns it off. As discussedbelow, some functions (such as automatic login) may be enabled when thedevice is assembled.

The keys on each array 102, 104 are formed of individual keycaps 302 anda key base 304 that forms a substrate for all keys of the array. Thus,in the embodiment shown in FIG. 3, there are eight keycaps 302 (foureach for key array 102 and key array 104) and two key base substrates(one each for key array 102 and 104). In this embodiment, there are 2different sizes of keycaps; one for large keys such as key 112 and onefor smaller keys such as key 122. In one embodiment, keycaps 302 and keybases 304 are injection-molded from a thermoplastic. In one embodiment,they are molded from polycarbonate.

Each key is associated with at least three primary functions. Forexample, key 112 is associated with R, T, F, G, V and B as its primaryletter functions. Each key is spaced at 19 mm from its neighboring key,consistent with international standards for touch-typing. The characterlegends on a single key are closer together to reduce the throw distancefor the character selections by a same single finger. Tests indicatethis reduced throw lessens the physical work and contributes to fastertouch-typing. In one embodiment, zones, which may overlap, are definedon each key such that actuation of the key by a finger within the zonetriggers the actuation of the associated function. For example, pressingthe lower right hand corner of key 112 would fall within the B zone andresult in the key event actuating the B function. The zones may overlapsomewhat and a processor within the key array may interpret intent ofthe finger-press based on the percentage of the contact that fallswithin a particular zone. Because of the risk of accidental actuation ofmore than one function when a finger overlaps two zones, the processorinterprets any arbitrary combination of readings from one or more zoneson any physical key into a single unique function. While key 112 isshown as having six zones, keys such as key 122, which has only threeprimary functions E, D and C, may have only three zones. In oneembodiment, capacitive sensors within the substrate 304 sense the zoneor zones of contact and that information is interpreted by a processorwithin the array. In one embodiment, the internal processor maydynamically adjust the size of a zone associated with a function or theweighting of the readings associated with that same function. Suchdynamic adjustments to the interpretation by the processor may also bebased on one or more prior functions executed with the keyboard. Thisremapping can employ traditional predictive typing techniques so thatthe zones associated with a most probable next letter are made largerand less likely letter zones are made smaller. This dynamic zoneresizing can reduce the error rate when typing on the keyboard.

Spacebar 106 includes a cover 310 having a top surface 306. In oneembodiment, cover 310 includes an internally thinner region 308, which,while imperceptible externally, provides display functionalityresponsive to the actuation of, for example, LEDs within the spacebar106. LED's by nature have at least two states ON and OFF. Byappropriately using these LEDs it is possible to convey information,alerts etc to a user. This type of display may also be useful onconventional keyboards to unobtrusively convey information e.g. fromwithin the spacebar. This display may be used to, for example, showbattery life, communications status, caps lock state, or other usefulinformation to a user directly on the spacebar 106. Additionally, all orpart of the surface 306 may be provided with underlying capacitivesensors to detect gesture input. Gestures may be recognized byinterpreting readings at the different capacitive sensor locations overtime and comparing the signature of these readings to a reference in adatabase residing either in the keyboard or the host. A specificfunction can be assigned to each signature that is recognized. Suchfunctions can include control modes and settings local to the keyboard,or inputs to the host such as pinch-to-zoom, swipe-to-scroll or othergestures commonly used on today's touch pad computing devices.

Keyboard 100 has a footprint on the surface as deployed equal to thearea of the spacebar 106 plus the area of each key array 102,104. Theareas of the key arrays 102,104 can be decomposed into two rectangularareas and a triangle where they join together. In one embodiment, thefootprint of the deployed keyboard is less than 180 square cm. In oneembodiment, the spacebar has a dimension of 110 mm×30 mm, each key arrayhas a rectangular dimension of 94 mm×30 mm and the triangle has a heightof 16 mm and a base 30 mm.

FIG. 4 is a front view of a keyboard of one embodiment of the inventionwith one key depressed. Key 112 is shown in a depressed state. In oneembodiment, the key arrays have a rest state thickness of D and adepressed state thickness of D′. In one embodiment, D is less than 9 mm.In such an embodiment, D′ might be, for example, in the range of 6-8 mm.However, in one embodiment D is approximately 5 mm and D′ isapproximately 3 mm. In one embodiment, the key travel distance is suchthat in a fully depressed state the lower edge of the keycap issubstantially in contact with the supporting surface. Thus, in oneembodiment, the keycap has a height of 3 mm. This results in the minimumpossible depressed profile. Typically existing low profile mechanicalkeyboards have a key travel range of between 1 and 3 mm. Touchpad andmembrane keyboards travel less than 0.5 mm. In some embodiments, eachmechanical key may travel in the range of 0.5 mm. Various embodiments ofthe invention are expected to have key travel in the range of 0.5 mm-3mm. Thus, embodiments of the invention provide full travel keys with avery small form factor. It is expected that in most embodiments all keysin a particular embodiment will have a substantially identical traveldistance.

FIG. 5 is a diagram of a key base of one embodiment of the invention.Key base 304 of the left hand key array is depicted. The right hand keyarray is a mirror image of what is depicted in FIG. 5. Key base 304 ismolded as a single substrate for all four constituent keys of the keyarray. Molded as part of key base 204 are axle housings 558. Four axlehousings 558 are provided for each key location. Additionally, each keylocation includes a magnet. Key 112 includes magnet 512, key 122includes magnet 522, key 132 includes magnet 532 and key 142 includesmagnet 542. As described below, these magnets maintain the rest state ofkey, i.e., maintain the key in an up position until sufficient force isapplied to overcome the magnetic field of the magnet. Key 142 alsoincludes magnet 548. As described in more detail below, magnet 548(which has a corresponding magnet in the right hand key array) is usedto maintain the keyboard in a collapsed storage orientation. Theprocessor 562 is provided within key base 304 to interpret key pressevents. In one embodiment, the wall thickness of base 304 is locallythinner or removed to provide a recess into which microprocessor 562 mayseat.

FIG. 6 depicts a flex circuit for a key array of one embodiment of theinvention. FIG. 6 is a flex circuit corresponding to the key array ofFIG. 5. Space is provided to accommodate the magnets and axle housingsmolded into the base. The flex circuit provides multiple capacitivesensors to detect the location of a finger on each keycap, and couplesto the processor (562 of FIG. 5). By way of example, four capacitiveregions are defined for each large key such as key 112, where regions612, 614, 616 and 618 correspond to lower left, lower right, upper rightand upper left quadrants of the key, respectively. Based on the overlapcoverage of the respective capacitive region, when the key is depresseda respective determination of which function of the key that is desiredis interpreted by the processor. Although the key 112 in this examplehas four capacitive sensors, locations between the sensors can bedetected through interpolation. Using interpolation, 6 or more discretelocations for the finger can be detected. In the case of the smallerkeys such as key 132, in this embodiment only two capacitive regions areprovided: capacitive region 632 corresponding to the bottom of the keyand capacitive region 634 corresponding to the top of the key. Again,based on the capacitance in the different capacitive regions responsiveto depression of the key, and using interpolation, the processor is ableto interpret which function is desired and uniquely select thatfunction. The remaining keys have analogous corresponding capacitiveregions. Other embodiments of the invention may employ more ordifferently configured capacitive regions. However, it is desirable thatthe regions be constituted in a manner that permits identification ofunique functions associated with a particular area on the key surface,which areas are touched during a key press event.

FIG. 7 is a diagram of a key according to one embodiment of theinvention with the keycap removed. The capacitive sensing pad 720 mayoverlay key base 104. The capacitive sensing pad 720 detects when a keyis depressed. As the user's finger becomes more proximate to the sensingpad with the depression of the key, a detectable change in capacitanceoccurs allowing both the fact of depression and the location of thefinger during the depression event to be determined. Key base 304 alsodefines a plurality of axle housings 558 to rotationally engage axles708 of link members 702 and 704. Link members 702 and 704 engage eachother in an interleaved fashion through coupling members 712,722 of link702 and 714,724 of link 704. In one embodiment, coupling members 722 and724 are magnetic masses such as steel that can be attracted to anunderlying magnet (not shown) disposed in key base 104.

Link members 702,704 may be formed of a combination of steel and plasticusing an insert molding process. Generally a high rigidity plastic isselected. One suitable plastic is acetyl resin available under thetrademark DELRIN™ from Dupont Corporation. In some embodiments one linkmember may be somewhat longer than the other. However, it is preferredto keep the link member relatively short such that neither link memberexceeds a length of 70% of the maximum cross dimension of the keycap. Bymaintaining the relative shortness of the link members 202 and 204,flexion is minimized and the parallelism during key depression isimproved. In one embodiment, neither link 202 nor link 204 exceeds 50%of the maximum cross dimension of the keycap. In one embodiment, bothlink member 702 and 704 are identical such that they can be manufacturedin a single mold and simply flipped relative to one another for purposesof assembly. Each link member 702 and 704 defines a pair of pegs 710 toengage slots (not shown) in the keycap.

FIG. 8A is a cross-sectional diagram of a key of one embodiment of theinvention in a depressed configuration. When sufficient pressure isapplied to keycap 302, the magnetic masses, in this case couplingnumbers 714,722 (and 712,724 not visible in this figure), delaminatefrom magnet 532 resident in key base 304. In one embodiment, couplingmembers 712,722 and 714,724 are formed of a ferromagnetic metal such assteel. Steel has high rigidity and durability and is well suited forthis application. Other embodiments may have the coupling members madepartially or entirely from a non-magnetic material, but use a magneticmass disposed therein.

A magnet 532 may be selected to be a rare-earth magnet which generates asuitable magnetic field that can continue to exert magnetic force evenafter delamination of magnetic masses 712,722 and 714,724 from themagnet 532. The feel of pressing the key with this associated magneticforce curve has desirable tactile characteristics. In one embodiment, asuitable magnet generates the magnetic field that requires 35 to 70grams of finger force to cause delamination. An N52 magnet that measures10 mm by 1.4 mm×0.9 mm is sufficient to provide such force in the layoutshown.

In this sectional view, link axles 708 can be seen residing in axlehousing 558. Axles 708 are translationally fixed within axle housing 558however; they are able to rotate to permit depression/actuation of thekeycap 302. To accommodate the movement of the opposing end of the link,peg members 710 reside in slots 830 which permit the pegs to translateaway from the center of the key a sufficient distance to permit the keyto be fully depressed. In one embodiment, a gripping pad 820 may beapplied to the under surface of key base 304 to minimize movement of thekeyboard on a supporting surface. For example, in one embodiment,gripping pad 820 may be an elastomeric material with favorablefrictional characteristics on common surfaces such as wood, metal, andplastic. In one embodiment, the pad is made from silicone rubber.Gripping pad 820 may be adhered with a suitable adhesive to the key base304. In one embodiment several discrete gripping pads are appliedinstead of a single pad substantially coextensive with a lower surfaceof the base member 304.

FIG. 8B is a sectional diagram of the key of FIG. 8A in a rest stateorientation. By referring to this orientation as a “rest stateorientation,” Applicant intends to indicate that this is the state thekey will adopt absent the application of an external force. This mayalso be thought of as the “up” configuration. In this configuration,magnet 532 is sufficiently close to magnetic masses 722 and 724 to befunctionally laminated thereto. The back end of slots 830 in keycap 302limit the travel of pegs 710 when the key rises, and when magneticmasses 722 and 724 strike magnet 532, the two limits work in conjunctionto prevent the key from rising above the prescribed level in the reststate. Ledges 840 are molded into keycap 302 to retain pegs 710 in orderto fasten the keycaps to the base.

FIG. 9 is a cutaway view showing a single link of one embodiment in theinvention. Links 702 and 704 are mechanically connected by metal members712, 722, 714 and 724 (all visible in FIG. 7), which collectivelycomprise the “Coupling Members”. The mechanical connection of thesecoupling members is formed by the interleaving of upper member 712 andlower member 724, as well as the counterpart upper member 714 and lowermember 722. Magnet 532 is shown beneath the coupling members. Link 702(not shown in this Figure) would have mirror images of lower interleavedmember 714 and upper interleaved member 724 (e.g. member 712 and 722)such that the lower interleaved member 722 for link 702 (not shown inthis Figure) would overlay the magnet 532. Member 722 is also adjacentto lower interleaved member 724 and beneath upper interleaved member712. Similarly, the upper interleaved member 712 for link 702, wheninstalled is disposed above and in engagement with lower interleavedmember 724. Thus, in rest state, 722 and 724 (not shown) aresubstantially flush with and laminated via magnetic attractive force tomagnet 532.

FIG. 10 is a bottom view of a key of one embodiment of the inventionwith the key base removed. In this view can be seen links 702 and 704and their respective lower interleaved members 722 and 724. Upperinterleaved member 714 of link 704 resides in engagement with lowerinterleaved member 722. Link axles 708 are also visible

FIG. 11 is a sectional view of FIG. 10 with one link removed. In thisview, the sloped surface 1104 of hard stop 1004 is clearly visible. Thehard stops 1002 and 1004 may be molded as part of keycap 302. Thelink-facing surface 1102 is sloped such that when the key is depressedit is in contact with link member 702's sloped surface 1122. Link member704 (shown in FIG. 10) has a mirror image contact with a sloped surfaceon hard stop 1004. These two contact points serve to prevent translationof the keycap when it is at the bottom of its travel during anactuation. The risk of keycap dislodgement resulting from an offsetforce on the keycap is also reduced.

Referring again to FIG. 7, link members 702, 704 are maintained in therest state position by the magnetic field of the magnet underlyinginterleaved coupling members 712, 722, 714 and 724 which mutually engagein an interleaved fashion as previously described. Capacitive sensingpads 634 and 632 cover substantially the entire base of the key outsidethe magnetic region. Pegs 710 are intricately molded as part ofrespective link members and engages slots in the keycap when the keycapis installed. The described structure permits highly parallel key travelwhich minimizes tilt of the keycap regardless of where the depressionforce is applied. The capacitive pads 720 and 632 eliminate the need fora rubber dome spring which in the common configuration of key switchesgenerally leads to a less crisp, and inferior tactile sensation. Boththe capacitive pad and magnetic force source are wear-free and haveessentially infinite life. Additionally, the capacitive pads 720 and 632provide determination of a key press as well as the location of a fingeron the keycap when the key is pressed. Interpolation of the capacitancevalues detected on the two pads 720 and 632 can determine a range oflocations for the finger between the pads that is far more than merelythe two pad centers. This effectively allows for one key to providemultiple functions. In this embodiment, other keys may have a set of 4pads in each quadrant of the key, allowing for even finer determinationof the finger location. Other embodiments may extend this to greaterthan 4 pads per key.

FIG. 12 is a diagram of the spacebar with the cover removed. Spacebar106 includes a flex circuit 1202, which may include an array of LEDs1208 which can provide the display functionality mentioned in connectionwith FIG. 3 above. Additionally, flex circuit 1202 can providecapacitive sensing for gesture detection. The placement of the flexcircuit in the spacebar immediately below the cover permits gesturesensing on the surface of the spacebar, as the capacitive detectionoccurs without depression of the spacebar. Flex circuit 1202 alsocouples to terminals 1204 which permit charging of battery containedwithin the spacebar 106. The links 1212 and 1214 are levers thatinterleave to form a mechanical interconnection 1218. Links 1212 and1214 each laminate to a magnet to provide a force to retain the spacebarin the up position. As described in more detail below with reference toFIGS. 15A-C, pressure on the spacebar causes delamination of the leversfrom their magnets, which then relaminate when pressure is relieved.Also visible in this view is the topology of magnetic mass 206. Tomechanically interconnect the elements by magnetic force, a singlemagnetic mass is sufficient. This mass provides a magnetic force tomechanically join the spacebar 106 to the key arrays 102 and 104.Because the interconnection is also used to electrically pass power,ground and data between the key arrays and the spacebar 106, themagnetic mass is divided into submasses that form discrete electricalcontacts. 1226 is the center magnetic mass which provides a groundconnection. 1228 and 1224 are both connected to power and are separatedfrom the 1226 ground mass by an insulator. The assembly of the threesubmasses forms the complete magnetic mass 206. Mass 1224 couples tomagnet 202 (shown in FIG. 2), mass 1226 couples to both magnets 212 and214 and mass 1228 couples to magnet 204. The topology of magnetic mass1226, having a raised center and a two flanking bumps along an otherwiseflat surface where magnets 212 and 214 connect, has been found to ensurestrong magnetic connections while concentrating the mechanical force ona localized electrical contact point (i.e. the bumps). This is importantto ensure that the power and data paths remain well coupled during use.

FIG. 13 shows a flex circuit for a spacebar of one embodiment of theinvention. The flex circuit includes terminals 1304 which are coupled tothe charging terminals of the spacebar. The LEDs 1208 are also shown onthe flex circuit. A microprocessor 1302 is coupled to the flex circuitand is used to interpret keyboard events. Keyboard events include, butare not limited to, key press events, gesture events, spacebar eventsand the like. The microprocessor also controls the wireless signalingmodule such as a Bluetooth™ module to transmit keyboard events to ahost. Additionally, microprocessor 1302 may, in its onboard memory,store user-specific data such as passwords, unlocking codes and thelike. Microprocessor 1302 can then be used, for example, to unlock asmartphone from a stored password without the need for manually enteringthe code. This has the advantage that unlock codes (commonly four digitsfor most smartphones) can be made much longer and more robust, therebyimproving the security of the phone. In other embodiments, a separatememory may be provided to store such user specific data.

FIG. 14 is a further view of the spacebar with the cover and flexcircuit removed. Battery 1402, which is used to power the spacebar andkey arrays in one embodiment of the invention, occupies the majority ofthe space within the spacebar. Also within the spacebar is defined astorage space for the charging beam 208. At the opposite end is disposedthe wireless communications module 1404, which in one embodiment may bea Bluetooth™ module. A wireless communication module 1404 may be acommercially available Bluetooth™ module such as a BCM920730MD_Q40available from Broadcom™ Underlying the wireless signaling module 1404can be seen a piezoelectric speaker 1410, which functions both as aspeaker to provide audio output of the device and also provides apressure sensing function. A second speaker is disposed at the other endof the spacebar below the charging beam. With this balanced arrangement,these two pressure sensors 1410 work in concert as a scale to measurethe intensity of pressure applied to the spacebar 106. The piezo sensorsare also responsive to overall acceleration of the spacebar. Thus, inone embodiment, they are used to determine whether a spacebar inputevent has occurred. As described below, an event detected by thepressure sensors may also be used to stimulate an automatic loginprocedure or other arbitrary automatic script between a host orrecipient device.

In one embodiment, the battery is a lithium polymer rechargeable batteryhaving a cell potential of 3.7V, and a capacity of 350 mAh. It isanticipated that with normal use this battery will allow one embodimentof the invention about 70 hours of actual operation before requiring arecharge. A wireless signaling module 404 may be a commerciallyavailable Bluetooth™ module such as BCM920730MD, available fromBroadcom™. In this side view, it is possible to clearly see the bumps1424 and 1426 of magnetic mass 1226. By concentrating the force of themagnetic attraction into a small area of high mechanical pressure, thesebumps help ensure a reliable electrical connection between the permanentmagnets of the key array and the magnetic masses of the spacebar.

FIGS. 15A and 15B are diagrams of the link mechanism in an up and downorientation, respectively. Feet 1502 and 1504 support the spacebarelevated above the table. Opposing ends of levers 1212 and 1214 aremechanically linked at interconnection 1218, which in one embodimentcorresponds to four coupling members comprising two pairs of upper andlower fingers. Levers 1212 and 1214 laminate to magnets 1508, which biasthe spacebar into an up position. When sufficient pressure is applied tothe spacebar, the feet 1502 and 1504 retract into the spacebar asrespective levers 1212 and 1214 rotate about axles 1512 and 1514,causing them to delaminate from magnets 1508. A spacebar depressionevent may be detected by a capacitive sensor or electrical contact onflex circuit 1202 or, for example, by detection of a pressure oracceleration event at the pressure sensors (discussed above). Theprocessor, as a result of the detection of the spacebar event, transmitsthe spacebar depression event to the recipient device.

FIG. 15C is a sectional view of the interconnection between the spacebarand the key arrays. Magnetic mass 206 couples to magnet 212 of key array102. The magnetic mass is contained in a structure attached to axle 1520but remains static relative to relative to magnet 212. The remainder ofspacebar 106 rotates about axle 1520 in response to a spacebardepression event. Because the contact bumps remain in strong staticmechanical contact during the motion of the spacebar, this ensures thatthe electrical connection is not broken. Further, this eliminates wipingwear on the contact surfaces even during repetitive cycling of thespacebar from depression events. Thus, the spacebar 106 rotates aboutthe axle 1520 during depression rather than translating. While oneembodiment of the invention may avoid this axle mechanism and fix themagnetic mass directly to spacebar 106, due to the high number ofexpected usage cycles for the spacebar and the desirability ofmaintaining a reliable mechanical and electrical connection with the keyarrays, it is preferred to avoid moving the magnetic mass relative toits permanent magnet counterparts A further benefit of this axle pivotarrangement is that it allows the adjacent edge of the spacebar toalways reside at the lower depressed state position, while the far edgeswings up and down about 2 mm for actuation. This permits the edge ofspacebar 106 to stay below the nearby keycap 112, eliminating collisionwith a user's finger during actuation of the key.

FIG. 16 is a perspective view of the spacebar with the beam 208partially removed. Beam 208 resides in the spacebar 106 in a stowagelocation sized for a snug fit such that the beam will not fall out ofits storage slot without an impulse force from a user. By applying animpulse force, a user can cause the beam to partially eject from theslot. A magnet disposed within the slot interacts with a magnetic strip1608 such that the beam will not eject free of the spacebar housing inresponse to a normal impulse force. End 1610 of beam 208 may be shapedto insert into a USB, mini-USB, or other port connector capable oftransmitting power to a connected device. This permits beam 208 to beconnected to a host to provide a charging path to the opposite end ofbeam 208. Also visible in this view are charging terminals 1604 and 1606of the spacebar. In one embodiment, charging terminals 1604 and 1606 areconstituted as permanent magnets.

FIG. 17 is a view of the beam coupled to a host and spacebar. The host1702 provides a port 1704 (such as a USB port, Thunderbolt port, 1394port or other port through which power may be passed to a peripheraldevice) compatible with the shape and contacts integrated into the endof beam 208. The rigid beam 208 eliminates the need for any flexiblecharging cable and is less than three inches in length. In oneembodiment it is 26.7 mm long and 12.4 mm wide. Magnetic masses 1708disposed at the opposing end of beam 208 interconnect with the magneticterminals of spacebar 106. Spacebar has only two connecting pins, andinternally adjusts the electrical polarity associated with each pin sothat the beam can be attached in an arbitrary orientation.

Additionally, because the angle and orientation of the magneticinterconnection is variable, it permits the spacebar to be coupled tothe host in a range of angles θ without breaking the interconnection. θcan vary by more than 180 degrees to work around nearby obstructionsfrom a tabletop, neighboring connectors, and the host housing. Notably,the connection can also breakaway in response to an applied forceintentional or unintentional without damaging the beam or device. Thisallows the device to be charged in space-constrained environments.Additionally, the magnetic interconnection is sufficiently strong tosustain the weight of the spacebar 106 and maintain electricalconnection to the host even when otherwise unsupported. While the host1702 in this instance is shown as a laptop computer, the host could be adesktop computer or need not be a computer at all: for example, thehost, for charging purposes, may be a powered USB hub, or an AC walladapter.

FIG. 18 is a perspective view of one embodiment of the invention in astowed orientation. As shown in this view, clip 324 retains the spacebar106 and two key arrays 102 and 104 in a parallel stack. Also visible inthis view is a jaw 1802 of clip 324, which allows a recipient device tobe held at a desirable angle for viewing. The recipient device may be ahost such as a smartphone or tablet computer. When inserted into theclip 324, the key arrays 102 and 104 have their keys depressed, therebyreducing the volume of the stack. Because the clip only covers one end,the far end keys have a tendency to expand as they seek the rest state(up orientation). However, as alluded to above with reference to FIG. 5,an additional magnet 548 attracts to its counterpart magnet in the otherarray to collapse the keys and hold them in a depressed state duringstowage. In one embodiment, even absent the clip 324, the two key arraysand the spacebar can collapse and retain themselves in a compact bundleunder the force of the integral magnets. Magnets 212 and 214 alsoattract the other ends of the two key arrays 102 and 104, and retainthem together sufficiently to compress their keys to their depressed andmost compact state. Moreover magnets 212, 214, and 548 all can attractmagnetic material in the spacebar, such as a 430 alloy stainless steelbackplate. In this manner, a three layer stack of two key arrays and thespacebar are effectively magnetically self-propelled into properalignment, such that the keyboard collapses itself into a singleself-retaining portable bundle that occupies a minimum volume. It isbelieved that this “packageless” magnetic packing is useful for otherelectronic devices with dissociable elements where the individualelements require a different spatial arrangement during use as comparedwith their compact storage arrangement. This volume is equal to thedepressed dimension of the two key arrays plus the spacebar thickness.In one embodiment, the spacebar with the two depressed key arrays has athickness of about 10 mm. In one embodiment, while strictly speaking,the clip 324 is not necessary to hold the dissociable parts together fortransport, it provides a protective cap for the magnetically coupleddissociable elements and a smooth surface to ease entry into a pocketand also provides a stand for a recipient device. In one embodiment theadditional volume associated with the clip may be less than 10% of thetotal collapsed volume of the device. In one embodiment, the additionalvolume of the clip is between 1 and 3%.

Generally, the keyboard is the shape of a narrow candy bar when stowed.In one embodiment, the collapsed volume of the keyboard plus clip isless than a bounding volume 1810 of about 35 cubic centimeters. Otherembodiments may be in the range of 25 to 180 cubic centimeters. It ispreferred that the collapsed volume be less than 80 cubic centimeters.As reflected in the drawing, bounding volume as used here is intended torefer to the volume of a minimum rectangular solid that can enclose adevice. Thus, the bounding volume does not omit interstitial spacesinterior between elements of the device as would be the case under astrict Archimedes principle analysis.

When disassembled the keyboard then enters a low-power idle state toconserve battery life. Some functionality may still be maintained evenin this state. For example, some embodiments provide an automatic loginfunction and a device range alert as discussed more fully with referenceto FIG. 20 below. These functions, as well as for example, a batterystatus check responsive to a user request (such as a pressure sensorevent) may be maintained by the processor while it is substantiallyasleep. In one embodiment, a pressure event registered by thepiezoelectric speaker 1410 will cause microprocessor 1302 to calculatethe remaining charge in the battery and generate a bar graph in responseappearing on the array of LEDs 1208.

FIG. 19 is a perspective view of the bottom side of the clip. Clip 324includes an elastomeric or otherwise nonslip pad 1902 on a lower surfacethereof to prevent slippage when a recipient device is installed in jaw1802. In one embodiment, clip 324 is injection-molded from thermoplasticand the nonslip pad is silicone rubber applied with an adhesive backing.

FIG. 20 is a flow diagram of the operation of one feature of oneembodiment of the invention. At block 2002, the keyboard detects andpairs with a host/recipient. By way of example, the keyboard may pairvia Bluetooth™ with a smartphone or tablet computer when the keyboardcomes within range of such device. At decision block 2004, the keyboarddetermines whether automatic login is enabled for the device. Ifautomatic login is enabled for the device, a determination is madewhether the keyboard is in a deployed configuration at decision block2006. By way of example, the spacebar knows whether the key arrays areconnected or not connected to it at any given time. If the keyboarddetects a pressure event or if the keyboard is deployed, it mayautomatically send sufficient information to unlock the host at block2010. Other arbitrary events may be used to trigger the automatic loginprocedure when the host is within range of the keyboard.

Thereafter, a determination is made whether the host is greater than athreshold distance from the keyboard at decision block 2012. As long asthe host is not at a distance greater than the threshold from thekeyboard, a further determination is made whether a logout has occurredat block 2018. If the logout has occurred at decision block 2018, theprocess returns to determine whether or not automatic login is enabled.However, if no logout has occurred, the process continues with a furtherdetermination of whether the host is at a distance greater than thethreshold at block 2012. Assuming that the host has traversed a distancegreater than the threshold from the keyboard, at block 2014, thekeyboard signals an alert. This may take the form of an audible alert, avisual alert such as flashing of the LEDs or both. It is also possiblethat the alert may vary depending on whether the keyboard is deployed ornot. For example, if the keyboard is deployed, the alert may be visiblewith the LEDs flashing. Alternatively, if the keyboard is stored, thealert could be audible under the presumption that a user would not see avisible alert in that configuration.

Additionally, at block 2016 the keyboard prompts the host to signal itslocation. This may be prompting the host to emit an audible tone, avisual signal, vibrate, etc. In this manner, risk of loss or theft of ahost device is reduced. In another embodiment, regardless of thedistance between the host and keyboard, at least one element of thekeyboard is used to send a signal to the host which causes the host toemit a sound or vibration or other alert. This function may beconfigured to operate whether or not the host has its alert speaker orvibrator enabled. This can be achieved for example by accessing themusic playing controls of the host smartphone even while the smartphoneis in a sleep state, and causing the volume to be maximized and a songto be played as the alert. Use of this function allows a user to locatea nearby smartphone, for example, that is obscured by its surroundings.Such a function can be realized without modifying the standard softwareconfiguration of the smartphone, and can be activated entirely withkeycode commands in automated scripts issued by the keyboard.

It should be appreciated that reference throughout this specification to“one embodiment” or “an embodiment” means that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present invention.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the invention.

In the foregoing specification, the embodiments of the invention havebeen described with reference to specific embodiments thereof. It will,however, be evident that various modifications and changes can be madethereto without departing from the broader spirit and scope of theinvention as set forth in the appended claims. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thana restrictive sense.

What is claimed is:
 1. An apparatus comprising: a keyboard for touchtyping having a home row of locations for each of 8 fingers to restconcurrently, and providing single stroke access to every letter of afull alphabet, the keyboard having a plurality of mechanical keys, eachkey having a surface area for actuation by a finger, and each key mapsto at least three functions and each key can move at least 1.0 mmresponsive to sufficient pressure by the finger, wherein the key surfaceremains substantially parallel to a rest plane while the key moves toaccess each letter associated with the key, and wherein the rest planeis a plane defined by the key surface in the absence of an actuationforce; and wherein each function is associated with a sensing zone thatis defined by a virtual boundary circumscribing a portion of the surfacearea of the physical key; and wherein a key function is selected basedon the location of the finger relative to the sensing zones duringactuation of the key; and wherein at least some adjacent sensing zonesoverlap one another such that an intersection of their virtualboundaries circumscribes a subportion of the surface of the key; andwherein when a single zone is completely covered by the finger duringactuation, the input resolves to a single function associated with thatzone.
 2. The apparatus of claim 1 further comprising: a plurality ofcapacitive sensors at least one of which is uniquely associated witheach key, to allow determination of a specific sublocation of a fingerwithin a surface bounded by a perimeter of the key.
 3. The apparatus ofclaim 1 further comprising a visual display with a plurality of elementswithin one or more zones, each element having at least two visualstates, wherein in one state the display is substantially imperceptiblerelative to a remainder of a key surface, and in another state thedisplay is visible.
 4. The apparatus of claim 1 wherein the surface of akey contains a local tactile feature fixed in relation to the zoneswithin the key, which feature allows a user to recognize a locationwithin the key surface by touch.
 5. The apparatus of claim 4 wherein thelocal tactile features are concave wells arranged in correspondence to 8user fingertip locations defining home row positions for the touch typekeyboard.
 6. The apparatus of claim 1 further comprising a controller todynamically remap the size and location of one or more of the zones. 7.The apparatus of claim 1 wherein the keyboard can operate in anenvironment containing plural wireless hosts, and wherein a user inputdefines which host is selected to receive the output from the keyboard.8. The apparatus of claim 1 wherein a sum of the individual areasdefined by the virtual boundaries of the sensing zones is greater thanthe total surface area of the physical key.
 9. The apparatus of claim 1wherein the keyboard has a deployed configuration and a collapsedconfiguration and wherein the collapsed configuration can fit within abounding volume of less than 180 cubic centimeters.
 10. The apparatus ofclaim 9 further comprising: a controller within the keyboard, whereinthe controller retains a user-defined password; and wherein thecontroller can automatically send a user-defined password to theselected host in both the deployed and collapsed configuration withoutthe need for a manual password entry or biometric input.
 11. Theapparatus of claim 1 wherein a zone of actuation of the finger mayoverlap with multiple zones and a single function is selected by atleast in part interpreting the pattern of finger overlap with themultiple zones.